Sharp R-390B Service Manual
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Sharp R-390B Service Manual

Sharp R-390B Service Manual

Microwave oven
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CAUTION, MICROWAVE RADIATION ............................................................................................................. 1
WARNING .......................................................................................................................................................... 1
PRODUCT SPECIFICATIONS ......................................................................................................................... 2
GENERAL INFORMATION ................................................................................................................................ 2
APPEARANCE VIEW ....................................................................................................................................... 3
OPERATION SEQUENCE ................................................................................................................................ 4
FUNCTION OF IMPORTANT COMPONENTS ................................................................................................ 6
SERVICING ...................................................................................................................................................... 7
TEST PROCEDURE ......................................................................................................................................... 9
TOUCH CONTROL PANEL ............................................................................................................................. 16
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ........................................................... 19
MICROWAVE MEASUREMENT .................................................................................................................... 25
WIRING DIAGRAM ......................................................................................................................................... 26
PICTORIAL DIAGRAM ................................................................................................................................... 27
POWER UNIT CIRCUIT .................................................................................................................................. 28
SWITCH UNIT ................................................................................................................................................. 29
DISPLAY UNIT CIRCUIT ................................................................................................................................. 30
PRINTED WIRING BOARD OF POWER UNIT AND SWITCH UNIT .............................................................. 31
PRINTED WIRING BOARD OF DISPLAY UNIT ............................................................................................. 32
PARTS LIST ................................................................................................................................................... 33
SERVICE MANUAL
MODEL
BACKWA RD
FORWAR D
INDEX
INSTANT COOK
SLOW COOK
START
STOP
CLEAR
1
2
3
4
5
6
7
8
9
0
In interests of user-safety the oven should be restored to its
original condition and only parts identical to those specified
should be used.

TABLE OF CONTENTS

SHARP CORPORATION
MICROWAVE OVEN
R-390B
R-390B
S6807R390BPJ/
Page

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  • Page 1: Table Of Contents

    R-390B SERVICE MANUAL S6807R390BPJ/ MICROWAVE OVEN R-390B MODEL BACKWA RD FORWAR D INDEX INSTANT COOK SLOW COOK START STOP CLEAR In interests of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used.
  • Page 2 R-390B...

  • Page 3: Caution Microwave Radiation

    MICROWAVE OVEN APPEARANCE VIEW R-390B GENERAL IMPORTANT INFORMATION This Manual has been prepared to provide Sharp Corp. Service OPERATING SEQUENCE engineers with Operation and Service Information. It is recommended that service engineers carefully study the entire text of this manual, so they will be qualified to render FUNCTION OF IMPORTANT satisfactory customer service.

  • Page 4: Product Specifications

    R-390B PRODUCT SPECIFICATIONS ITEM DESCRIPTION Power Requirements 230 - 240 Volts 50 Hertz Single phase, 3 wire earthed Power Consumption 1.5kW Power Output 1000 watts nominal of RF microwave energy (IEC 705) Operating frequency 2450 MHz Case Dimensions Width 520 mm...

  • Page 5: Appearance View

    R-390B APPEARANCE VIEW INDEX START POPCORN MINUTE PLUS STOP CLEAR 1. Ventilation openings 9. Touch control panel 2. Oven lamp 10.Digital readout 3. Door hinges 11.Wave guide cover 4. Door safety latches 12.Power supply cord 5. See through door 13.Rating label 6.

  • Page 6: Operation Sequence

    R-390B OPERATION SEQUENCE OFF CONDITION 5. When the door is opened during a cook cycle, the switches come to the following condition. Closing the door activates 1st. latch switch, 2nd. latch switch and stop switch. (In this condition, the monitor CONDITION switch contacts are opened.)
  • Page 7 R-390B SENSOR COOKING CONDITION the power transformer, oven lamp, etc. are turned off. 6. Opening the door or touching the STOP/CLEAR key, Using the Sensor Cooking function (See sensor cooking the home page will reappear on the display and the menus), the foods are cooked without figuring time, power oven will revert to an OFF condition.

  • Page 8: Function Of Important Components

    R-390B FUNCTION OF IMPORTANT COMPONENTS The rated peak reverse voltage of D1 of the asymmetric DOOR OPEN MECHANISM rectifier is 6 KV. The rated peak reverse voltage of D2 of The door is opened by pushing the open button on the the asymmetric rectifier is 1.7KV.

  • Page 9: Servicing

    If the water remains cold carry out 3D checks and re- examine the connections to the component being Sharp recommend that wherever possible fault-finding tested. is carried out with the supply disconnected. It may in, some cases, be necessary to connect the supply after...
  • Page 10 R-390B CK = Check / RE = Replace TEST PROCEDURE A B C D E E E E G F H H I K L M N RE CK CK RE CK CK CK CK CK POSSIBLE CAUSE DEFECTIVE PARTS...

  • Page 11: Test Procedure

    R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER MAGNETRON TEST NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL WHILE THE OVEN IS IN OPERATION. CARRY OUT 3D CHECK. Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.
  • Page 12 R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER Initial temperature ..................... T1 = 11 C Temperature after (42 + 2) = 44 sec..............T2 = 21 C Temperature difference Cold-Warm .............. T1 = 10 C Measured output power The equation is “P = 100 x T” ........... P = 100 x 10 C = 1000 Watts JUDGMENT: The measured output power should be at least 15 % of the rated output power.
  • Page 13 R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER in either direction, then the asymmetric rectifier is probably faulty and must be replaced with high voltage rectifier. When the asymmetric rectifier is defective, check whether magnetron, high voltage rectifier, high voltage wire or filament winding of the power transformer is shorted.
  • Page 14 R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER MONITOR RESISTOR TEST CARRY OUT 3D CHECKS. Disconnect the leads from the monitor resist. Using an ohmmeter and set on a low range. Check between the terminals of the monitor resistor. The resistance of monitor resistor is approx. 0.8 ohms.
  • Page 15 R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER TOUCH CONTROL PANEL ASSEMBLY TEST The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter.
  • Page 16 R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER The meter should indicate 230 - 240 volts, if not check oven circuit. RY1 and RY2 Relay Test These relays are operated by D.C. voltage Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
  • Page 17 R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER Water load cooking test Make sure the oven has been plugged in at least two minutes before checking sensor cook operation. The cabinet should be installed and screws tightened. (1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.

  • Page 18: Touch Control Panel

    R-390B TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER Plunger R1,R2 : 22 1% 1/2W R3 : 10k 5% 1/4W R4 : 1M 5% 1/4W To connector (F) on Control Unit. Select switch CONNECTOR Sensor Dummy Resistor Circuit TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units.
  • Page 19 R-390B ABSOLUTE HUMIDITY SENSOR CIRCUIT compares it with its initial value, and when the (1) Structure of Absolute Humidity Sensor comparison rate reaches the preset value (fixed for The absolute humidity sensor includes two thermistors each menu to be cooked), the LSI causes the unit to as shown in the illustration.
  • Page 20 R-390B SERVICING 1. Precautions for Handling Electronic Components control panel with a jumper, which brings about an opera- This unit uses CMOS LSI in the integral part of the circuits. tional state that is equivalent to the oven door being When handling these parts, the following precautions closed.

  • Page 21: Component Replacement And Adjustment Procedure

    Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any of the following removal procedures: WARNING FOR WIRING and Oven cavity. To prevent an electric shock, take the following 3) Sharp edge: manners. Bottom plate, Oven cavity, Waveguide flange, 1. Before wiring, Chassis support and other metallic plate.
  • Page 22 R-390B HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR REMOVAL 1. CARRY OUT 3D CHECKS. 8. Disconnect rectifier terminal from capacitor. 2. Disconnect the brown and blue wires of power supply Rectifier and high voltage assembly is now free. cord from the noise filter.
  • Page 23 4. Where the corners have been snipped off bend corner areas flat. No sharp edge must be evident after removal NOTE: The one (1) screw to fit the turntable motor cover of the turntable motor cover.
  • Page 24 R-390B 9. Remove the fan blade from the fan motor shaft according 2. Install the fan blade to the fan motor shaft according to to the following procedure. the following procedure. 1) Hold the edge of the rotor of the fan motor by using a 1) Hold the center of the bracket which supports the shaft pair of grove joint pliers.
  • Page 25 R-390B Refer to "PICTORIAL DIAGRAM". Re-install 3. Secure latch hook (with two (2) mounting screws) to 1. Re-install each switch lever and latch switch in its oven flange. place. The 1st. latch /stop/monitor switches are in the 4. Make sure that the monitor switch is operating properly lower position and the 2nd.
  • Page 26 R-390B about how to handle new one. SEALER FILM 6. Catch two (2) pins of door panel on two (2) hole of upper Installation and lower oven hinges. 1. Put the adhesive tape on the backing film of the sealer 7.

  • Page 27: Microwave Measurement

    R-390B MICROWAVE MEASUREMENT After adjustment of door latch switches, monitor switch Recommended instruments are: and door are completed individually or collectively, the NARDA 8100 following leakage test must be performed with a survey NARDA 8200 instrument and it must be confirmed that the result meets...

  • Page 28: Wiring Diagram

    R-390B SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED NOTE: " " indicates components with potentials above 250V. 2. CLOCK APPEARS ON DISPLAY COM. N.O. Figure O-1. Oven Schematic-OFF Condition SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED 2. COOKING TIME PROGRAMMED 3.

  • Page 29: Pictorial Diagram

    R-390B RECTIFIER H.V. RECTIFIER ASYMMETRIC...

  • Page 30: Power Unit Circuit

    R-390B D1-D4 11ES1 – – AC230-240V 50Hz 2SB1238 – 2SB1238 TURNTABLE R5 3.3k MOTOR R4 1.3k OVEN LAMP MOTOR N.O. MICRO Q3 DTD143ES C6 10 /35v – NOTE : IF NOT SPECIFIED, 1/4w : IF NOT SPECIFIED, 1SS270A Figure S-2. Power unit Circuit...

  • Page 31: Switch Unit

    R-390B...

  • Page 32: Display Unit Circuit

    R-390B DOT) (100 A057DR driver) (LCD HD6610B /25v C122 /25v C121 /25v C134 0.01 C133 C110 4.7k C132 R110 C131 4.7k R160 C130 R130 R131 R132 R133 R134 R135 3.6kF R136 R137 IZA905DR 4.7k R102 /25v C135 BQ306-30316A LMP1 LMP2 4.7k...

  • Page 33: Printed Wiring Board Of Power Unit And Switch Unit

    R-390B (J3) (J2) OMIF OMIF BROWNER DOOR SH-A SH-B (GREEN) SW14 SW15 SW13 SW11 SW12 SW10 Figure S-5. Printed Wiring Board of Power Unit and Switch Unit...

  • Page 34: Printed Wiring Board Of Display Unit

    R-390B SW19 R143 LMP1 SW21 R142 R141 SW20 C123 LMP2 SW18 SW17 R140 CN - C Front side TP38 R135 C120 R110 C134 R180 R134 C121 C110 C133 C122 TP34 C132 R133 R51R52 R132 C131 R131 R137 C130 Q140 R130...

  • Page 35: Parts List

    R-390B PARTS LIST Note: The parts marked " " may cause undue microwave exposure. The parts marked "*" are used in voltage more than 250V. REF. NO. PART NO. DESCRIPTION Q'TY CODE ELECTRIC PARTS 1- 1 QSW-MA131WRE0 1st. latch switch, 2nd. latch switch and stop switch...
  • Page 36 R-390B Note: The parts marked " " may cause undue microwave exposure. The parts marked "*" are used in voltage more than 250V. REF. NO. PART NO. DESCRIPTION Q'TY CODE 3- 3- 1 FW-VZA219DRE0 Lead wire harness (CN-G) 3- 3- 2...
  • Page 37 R-390B HOW TO ORDER REPLACEMENT PARTS To have your order filled prompty and correctly, please furnish the following information. 1. MODEL NUMBER 3. PART NO. 2. REF. NO. 4. DESCRIPTION PACKING AND ACCESSORIES TOP PAD ASSEMBLY FPADBA311WRK0 DOOR PROTECTION SHEET...
  • Page 38 R-390B OVEN AND CABINET PARTS 4-20 1-11 1-10 4-18 4-17 4-10 1-17 1-13 4-16 4-19 4-15 4-12 4-13 4-14 1-12 1-15 4-11 1-14 4-15 1-16...
  • Page 39 R-390B CONTROL PANEL PARTS 3 - 2 3- 5 3- 9 3-2-7 3- 4 3-13 3-2-9 3- 8 3- 1 3-10 3-13 3- 3 3- 7 3-13 3-3-1 3-12 3-13 3- 6 3-11 3-3-2 4-21 5-10 DOOR PARTS MISCELLANEOUS (CAPACITOR) 6-10 Actual wire harness may be different from illustration.
  • Page 40 R-390B '98SHARP CORP. (6S0.720E) Printed in Australia...

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